CVE-2026-33799: CWE-787 Out-of-bounds Write in Juniper Networks Junos OS
An Out-of-bounds Write vulnerability in the SNMP daemon (snmpd) of Juniper Networks Junos OS and Junos OS Evolved allows an authenticated network-based attacker sending specific valid SNMPv3 queries to trigger a memory leak. Over time, continuous receipt of these queries will result in snmpd process memory exhaustion, resulting in a process crash and restart, impacting the ability to monitor the system via SNMP. Memory usage can be monitored using the following command: user@device> show system processes extensive | match snmpd This issue affects: Junos OS: * all versions before 21.2R3-S8; * from 21.4 before 21.4R3-S7; * from 22.1 before 22.1R3-S6; * from 22.2 before 22.2R3-S4; * from 22.3 before 22.3R3-S3; * from 22.4 before 22.4R3-S2; * from 23.2 before 23.2R2; * from 23.4 before 23.4R2. Junos OS Evolved: * all versions before 21.2R3-S8-EVO; * from 21.4 before 21.4R3-S7-EVO; * all versions of 22.1-EVO, * from 22.2 before 22.2R3-S4-EVO; * from 22.3 before 22.3R3-S3-EVO; * all versions of 22.4-EVO, * from 23.2 before 23.2R2-EVO; * from 23.4 before 23.4R2-EVO.
AI Analysis
Technical Summary
This vulnerability (CWE-787) exists in the SNMP daemon of Juniper Networks Junos OS and Junos OS Evolved. Authenticated attackers can send crafted SNMPv3 queries that cause an out-of-bounds write, resulting in a memory leak. Over time, this memory leak exhausts the snmpd process memory, causing it to crash and restart repeatedly. This disrupts the ability to monitor the system via SNMP. Multiple versions of Junos OS and Junos OS Evolved are affected, with fixed versions starting from 21.2R3-S8 and equivalent releases for subsequent versions. The vendor manages remediation for this cloud-hosted service.
Potential Impact
The vulnerability leads to a denial of service condition on the SNMP daemon by exhausting its memory and causing process crashes and restarts. This impacts system monitoring via SNMP but does not affect confidentiality or integrity. There are no known exploits in the wild as of the published date.
Mitigation Recommendations
A patch is available for this vulnerability. The vendor manages remediation for this cloud-hosted service, so users should ensure their Junos OS and Junos OS Evolved instances are updated to the fixed versions listed. Monitoring snmpd memory usage can help detect exploitation attempts. Check the vendor advisory for the latest patch and update instructions.
CVE-2026-33799: CWE-787 Out-of-bounds Write in Juniper Networks Junos OS
Description
An Out-of-bounds Write vulnerability in the SNMP daemon (snmpd) of Juniper Networks Junos OS and Junos OS Evolved allows an authenticated network-based attacker sending specific valid SNMPv3 queries to trigger a memory leak. Over time, continuous receipt of these queries will result in snmpd process memory exhaustion, resulting in a process crash and restart, impacting the ability to monitor the system via SNMP. Memory usage can be monitored using the following command: user@device> show system processes extensive | match snmpd This issue affects: Junos OS: * all versions before 21.2R3-S8; * from 21.4 before 21.4R3-S7; * from 22.1 before 22.1R3-S6; * from 22.2 before 22.2R3-S4; * from 22.3 before 22.3R3-S3; * from 22.4 before 22.4R3-S2; * from 23.2 before 23.2R2; * from 23.4 before 23.4R2. Junos OS Evolved: * all versions before 21.2R3-S8-EVO; * from 21.4 before 21.4R3-S7-EVO; * all versions of 22.1-EVO, * from 22.2 before 22.2R3-S4-EVO; * from 22.3 before 22.3R3-S3-EVO; * all versions of 22.4-EVO, * from 23.2 before 23.2R2-EVO; * from 23.4 before 23.4R2-EVO.
CVSS v3.1
Score 4.3medium
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CWE-787) exists in the SNMP daemon of Juniper Networks Junos OS and Junos OS Evolved. Authenticated attackers can send crafted SNMPv3 queries that cause an out-of-bounds write, resulting in a memory leak. Over time, this memory leak exhausts the snmpd process memory, causing it to crash and restart repeatedly. This disrupts the ability to monitor the system via SNMP. Multiple versions of Junos OS and Junos OS Evolved are affected, with fixed versions starting from 21.2R3-S8 and equivalent releases for subsequent versions. The vendor manages remediation for this cloud-hosted service.
Potential Impact
The vulnerability leads to a denial of service condition on the SNMP daemon by exhausting its memory and causing process crashes and restarts. This impacts system monitoring via SNMP but does not affect confidentiality or integrity. There are no known exploits in the wild as of the published date.
Mitigation Recommendations
A patch is available for this vulnerability. The vendor manages remediation for this cloud-hosted service, so users should ensure their Junos OS and Junos OS Evolved instances are updated to the fixed versions listed. Monitoring snmpd memory usage can help detect exploitation attempts. Check the vendor advisory for the latest patch and update instructions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- juniper
- Date Reserved
- 2026-03-23T19:46:13.673Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
- Is Cloud Service
- true
Threat ID: 6a50101d68715ace43153c58
Added to database: 07/09/2026, 21:18:21 UTC
Last enriched: 07/17/2026, 09:57:25 UTC
Last updated: 08/22/2026, 18:10:04 UTC
Views: 82
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